1. Field of the Invention
This invention relates to a light guide plate and a backlight module having the same and specifically relates to a light guide plate with prisms disposed on its lateral sides and a backlight module having the same.
2. Description of the Prior Art
Backlight module, as an essential element of the liquid crystal display (LCD), is used to provide adequate and uniform luminance for the LCD panel to properly display images. Especially after the LCDs have become the mainstream flat display devices, the luminance efficiency of the backlight module becomes an important factor affecting the overall performance of the LCDs.
FIG. 1A and FIG. 1B are a top view and a side view of a conventional backlight module 10, wherein a light source 11 is disposed next to one side of the light guide plate 12. As FIG. 1B shows, the light source 11 emits light toward the light guide plate 12, wherein the light includes at least light A and light B. The light guide plate 12 of the conventional backlight module 10 further includes a first optical layer 13 and a second optical layer 14 for allowing light A to exit from the top surface of the light guide plate 12 to form a planar light.
However, for the conventional backlight module 10 illustrated in FIG. 1A and in FIG. 1B, there is still light B not processed by the first optical layer 13 or the second optical layer 14. Light B then exits from the lateral side of the light guide plate 12 resulting in a loss of luminance and a waste of light energy.